Existing phased array antenna systems that incorporate antenna-integrated printed wiring board assemblies, such as those described in U.S. Pat. No. 6,670,930, utilize single or multi-layer printed wiring boards throughout the waveguide portion of the system. The printed wiring boards used in such systems are generally constructed of dielectric material that insulate heat. Heat generated by electronics integrated in the printed wiring boards does not easily dissipate through the waveguide portion and can degrade the performance of the system. For example, excess heat can cause lower Effective Isotropic Radiated Power (EIRP), higher noise, and limit the power level per unit cell. In addition, existing systems which utilize a cage-like conductive structure for the antenna element, also know as the “can,” have a limited upper frequency of operation. It is desirable to provide a phased array antenna system which incorporates multi-layered printed wiring board assemblies that can operate at a higher upper frequency and more effectively dissipate heat through the waveguide portion, which can thereby allow, for example, an increase in power level per unit cell and better performance of the system.